On average, they lived some 92.5 years where the average U.S. citizen lives to 78.3.
You're making a mathematical error here.
These people were on average 81 years old (and still alive) when the picture was taken. So, of course THEIR average lifetime will be higher than 78.3 years. You can also take 20 other people who are already 80 years old - their average lifetime must of course be higher than 80 years.